Apparatus for stretching and crimping fibers



- 1969 c. E. GORECKI 3,422,492

APPARATUS FOR STRETCHING AND CRIMPING FIBERS Filed Feb. 23, 1965 ATTORNEYS.

United States Patent 3,422,492 APPARATUS FOR STRETCHING AND CRIMPING FIBERS Charles E. Gorecki, Paoli, Pa, assignor to Heplon Inc.,

Wilmington, DeL, a corporation of Delaware Filed Feb. 23, 1965, Ser. No. 434,303

US. Cl. 181 5 Claims Int. Cl. B29c 24/00 ABSTRACT OF THE DISCLOSURE Apparatus are disclosed for stretching and crimping synthetic fibers so that the crimp will have a sharp definition and the fibers will have a uniform dye index. The tow of fibers is alternately subjected to stretching and plasticizing, then crimped, and then the crimp is set in a steam chamber having idler rollers. The number of idler rollers used determines the time to which the fibers are exposed to the steam without reducing the speed of production.

This invention relates to apparatus for stretching and crimping fibers. More particularly, this invention relates to apparatus for stretching and crimping synthetic filament so as to impart desirable characteristics to filaments.

It is well known that many synthetic fibers obtain their desirable characteristics by imparting a stretch thereto. Depending upon the denier of the filaments, nylon, for example, should be stretched between four and seven times its original length so as to impart to it the desirable characteristics generally associated with nylon. Moreover, it is known that the desirable characteristics of nylon are further enhanced by placing a crimp in the fibers.

A substantial number of filaments or fibers is referred to as tow. Apparatus for stretching a tow of filaments is called a tow stretcher. The apparatus of the present invention includes a tow stretcher, and for example, is designed to stretch a tow having up to 500,000 total drawn denier.

It has been found that certain qualities of a synthetic fiber are affected by the manner in which it is stretched and crimped. Thus, the process and the apparatus used for accomplishing the process may affect the dye index of the fiber whereby the finished product would have variations of color even though the fiber comes from the same batch. Further, the method and apparatus used to stretch and crimp the material effects the number of crimps per inch and the quality of the crimp. It, therefore, is a general object of the present invention to overcome these and other disadvantages in present methods and apparatus for stretching and crimping synthetic fibers.

It is an object of this invention to provide a novel apparatus for stretching and crimping of synthetic fibers.

It is another object of the present invention to provide a novel apparatus for stretching synthetic fibers.

It is yet another object of the present invention to provide a novel apparatus for crimping synthetic fibers.

It is still another object of the present invention to provide a novel apparatus for stretching a synthetic filament by successively increasing the amount of stretch from a predetermined amount to a desired amount by subjecting the filaments to a controlled amount of frictional drag.

It is a further object of the present invention toprovide a novel apparatus for crimping synthetic fibers to get a crimp having a sharper definition.

Other objects will appear hereinafter.

For the purpose of illustrating the invention there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

Patented Jan. 21, 1969 ice The drawing illustrates a schematic diagram of the apparatus of the present invention.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown a tow stretcher and crimper designated generally as 10.

The apparatus 10 includes a creel stand 12 which rotatably supports a large number of unstretched synthetic filament packages commonly referred to as cheese. The filaments are drawn from the outer surface of the packages 14 and caused to pass through one of a plurality of holes 18 in a filament guide 16.

The filament of tow 20, which may be type 6 or type 66 nylon, are continuously drawn from the creel packages 14 through a first to-w stretching apparatus designated .generally as 22. The tow stretcher 22 consists of a plurality of drag rollers 24, 26 and 28 having a normal smooth finish or a sandblasted finish and a diameter of approximately fourteen inches. The drag rollers may be of the type disclosed in copending patent application Ser. No. 245,887 filed Dec. 19, 1962 and assigned to the same assignee as the present application. Thus, each of the drag rollers 24, 26 and 28 may be provided with means whereby they may be selectively locked or allowed to rotate freely as the filament passes over them in contacting relation. The tow is generally in the form of a sheet or layer as it passes over the various rollers. Each drag roller is a cylindrical drum and may have a standard smooth finish such as a or finish.

From the drag roller 28, the tow 20 passes around four driven rollers 30, 32, 34 and 36 in partial contact therewith. Each of the driven rollers 3036 is rotating at the same speed. For example, the rollers 3036 may be rotating at a velocity of 200 feet per minute. While the tow 20 is passing over the driven rollers, at least one of the drag rollers is locked or otherwise prevented from rotating so as to apply a frictional drag on the tow. This causes the tow to be stretched. The amount of stretch can be varied by unlocking or looking one or more of the drag rollers 24, 26 and 28 thereby varying the frictional drag on the tow. It should also be noted that means may be provided for merely slowing down the drag rollers rather than completely locking them from any rotation.

From the driven roller 36 the tow 20 is next passed through a plasticizing means which may be in the form of a radiant heater 38. A reflector 40 is associated with the radiant heater 38 to insure uniform heating of the tow 20. If nylon is the product being stretched, then the temperature of the heater may be adjusted to heat the tow 20 to a temperature of from between 130 C. to C. Alternative means for plasticizing the tow could be used. Thus, for example, a contact heater could be substituted for the radiant heater. However, the radiant heater is preferred as it permits better control and eliminates such problems as may arise if the heat source is defective in a contact heater.

From the plasticizing means, the tow 20 passes through a second tow stretcher 42. The tow stretcher 42 is similar in construction to the tow stretcher 22. Thus, it comprises selectively lockable drag rollers 44, 46 and 48 together with driven rollers 50, 52, 54 and 56. The tow stretcher 42 differs from the tow stretcher 22 in that the driven rollers 50-56 are rotated at a higher velocity than the driven rollers 3036. Thus, the driven rollers 50-56 may be rotated at a velocity of 350 to 550 feet per minute. The increased rotational speed compensates for the greater length produced by tow stretcher 22, and it also is sufficient to stretch the tow 20. Further, the drag rollers 44, 46 and 48 may be water cooled. For nylon the drag rollers 44, 46 and 48 are preferably cooled to a temperature of 5060 F.

The tow 20 passes from the second set of speed rollers through a plasticizing means which may be a radiant heater 58 and reflector 60. The radiant heater 58 operates at the same temperatures and in the same manner as the radiant heater 38. Moreover, any of the alternative plasticizing means heretofore mentioned may be used.

From the radiant heater 58, the tow 20 passes through a third tow stretcher 62. The third tow stretcher 62 is similar in construction to tow stretchers 22 and 42. Thus, tow stretcher 62 comprises drag rollers 64, 66 and 68 together with driven rollers 70, 72, 74 and 76. In tow stretcher 62 the driven rollers 7076 are rotated at a velocity of 650 to 850 feet per minute. The speed selected is sufficient to prevent slack in the tow 20 and to stretch the tow 20. Drag rollers 64, 66 and 68 are also water cooled to a temperature of 5060 F.

As the denier of the filaments increases, an increasing number of drag rollers must be locked or siowed down.

Depending upon the number of drag rollers utilized, the surface finish of the drag rollers, diameter of the drag rollers and the type of filaments being stretched, anyone skilled in the art may easily ascertain by simple tests the number of drag rollers in each roller set of the tow stretcher which must be locked as the function of the denier of the filaments.

As shown schematically by the dotted line, the stretched tow passes from the third tow stretcher 62 to the steam plasticizer 78. The steam plasticizer 78 has a funnel shape which groups the tow 20 in the form of a rope. A plurality of steam nozzles 80 are mounted on the steam plasticizer 78. The steam nozzles 80 are connected to a source of steam. The bottom of the steam plasticizer 78 slopes downwardly into an outlet tube 82 for permitting condensed steam to escape from the plasticizer 82.

From the steam plasticizer 78, the tow passes through a crimp box 84. The tow is pulled through the steam plasticizer and directed into the crimp box 84 by feed rolls 83 and 85 which gives a positive and controlled rate of feed into the crimp box 84. The nip rollers 86 and 88 serve to control the discharge from the crimp box 84 and provide a positive feed to the heater 90. The plasticizer 78 is adjusted to have a temperature of approximately 105 C. to 120 C.

From the nip rollers 86 and 88 the tow is pulled through a radiant heater 90 with a reflector 92. The radiant heater 90 preheats the tow 20 for setting the crimp in the crimp setter 94.

The crimp setter 94 comprises a steam chamber 96 having an inlet 98 and an outlet 100. Steam is sent into the steam chamber 96 through inlet 98 at a temperature of approximately 245-280 F. for setting type 6 nylon. The upper and lower limits of this range would be about 3540 F. higher for type 66 nylon. Condensed steam escapes from the chamber 96 through outlet 100. As used herein, the steam may be referred to as a fluid.

A plurality of idler rollers 110 are mounted in the chamber 96. As shown, the tow 20 passes over the idler rollers 110 in partial contact therewith. The idler rollers serve to retain the tow 20 within the chamber 96 for a sufiicient amount of time to permit the crimp to be set. Thus, although the illustrated diagram shows the tow 20 making partial contact with each of the idler rollers 110, it should be obvious that if it is desired to lessen the amount of time which the tow 20 is within the chamber 96, then it is only necessary to reduce the number of idler rollers with which the tow 20 makes contact.

The nip rollers 112 and 114 pull the tow 20 through the crimp setter 94. The nip rollers 112 and 114 are rotated at a velocity suflicient to retain the tow 20 taut against the idler rollers. From the nip rollers 112 and 114, the tow 20 may be collected in a container for packaging.

Using the apparatus and method described above, it has been found that the crimp in the fiber may have a sharper definition and more crimps per inch. The reason for this is believed to be because steam is applied to the tow before the tow enters the crimp box 84. It is believed that a more uniform steam penetration results therefrom Further, the use of a preheater together with the steam in steam chamber 96 and the ability to control the amount of time that the material is within the chamber 96 results in a sharper crimp definition as and if desired. Moreover, it has been found that the use of a combination of tow stretchers and plasticizer in alternating relationship results in a more uniform dye index for any particular batch of fiber.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. Apparatus for stretching filaments comprising a first means for stretching filaments including a plurality of freely rotatable drag rollers, each drag roller being adapted to be selectively locked, a plurality of driven rollers adapted to pull the filaments around a portion of the drag rollers with a portion of the filament in contact with said driven rollers, a second and third means for stretching filaments similar to said first means, said first, second and third means being in successive operative relationship for stretching the filaments, the driven rollers of said second means and the driven rollers of said third means being adapted to be rotated at successively higher speeds relative to the driven rollers of said first means, the speeds of said second and third driven rollers increasing in the direction of travel of the filaments, a filament plasticizing means operatively located between said first and second and between said second and third filament stretching means, crimping means operatively associated with said third filament stretching means for crimping the filaments stretched thereby, said crimping means including a crimp setting means, said crimp setting means including a steam chamber, means to introduce steam into said chamber, and a plurality of idler rollers mounted within said chamber, and means for pulling said filament serially around a portion of a predetermined number of said idler rollers.

2. Apparatus in accordance with claim 1 wherein each said filament stretching means includes three drag rollers and four driven rollers.

3. Apparatus in accordance with claim 1 wherein a filament plasticizing means is operatively located between said filament stretching means and said crimping means.

4. Apparatus in accordance with claim 1 wherein said first-mentioned plasticizing means are radiant heaters each having a reflective shield positioned so that the tow of filaments may pass therebetween.

5. Apparatus in accordance with claim 1 including means for rotatably supporting a plurality of spools of filaments, and means for guiding the filaments into a tow so that the tow of filament may be fed to said firstmentioned rollers.

References Cited UNITED STATES PATENTS 2,002,711 5/1935 Parkhurst et al. 264-294 X 2,216,142 10/1940 Taylor et al.

2,698,967 1/1955 Reichel et al. 264288 X 2,767,435 lO/1956 Alles 264-288 2,934,400 4/1960 Siggel et al.

2,957,748 10/1960 Lieseberg 264294 X 3,068,528 12/1962 Owens 264288 X 3,076,232 2/1963 Dengler 264288 3,092,891 6/1963 Baratti 264-290 X 3,107,140 10/1963 Kurzke et al. 264-290 3,263,298 8/1966 Holton 264290 X WILLIAM J. STEPHENSON, Primary Examiner. 

